1. Field of the Invention
The present invention relates to processes and apparatus for producing ozone from oxygen containing streams by chemonuclear irradiation.
2. Prior Art
The use of ozone as an oxidizing agent has long been known, but present day commercial techniques for the production of ozone are too expensive for most uses. However, the need to reduce environmental and health hazards has increased the demand for use of ozone. For example, potable water supplies for municipalities and/or industrial use which are drawn from surface water sources are traditionally treated with chlorine in order to destroy objectionable microbiological agents contained in the water. Additionally, the chlorination is often effective in reducing the odor and taste causing materials contained in surface originating water supply sources. Until recent years there has been no known adverse effect from this original chlorination treatment used almost universally all over the world for surface source potable water treatment. However, recent scientific investigations have shown that even with the very light chlorination that is utilized in treating surface waters for potable water use, such treatment causes a minute amount of chlorine contained in the water to react with man-made chemical effluents which have found their way into main stream water sources and also to react with naturally occurring, soluble, organic materials normally occurring in surface water derived from lakes and rivers, e.g., tannin type material from the decomposition of leaves, etc. Recent testing has shown that certain of these materials are believed to be carcinogens and the governmental agencies are taking steps to require municipalities and other entities to treat their chlorinated drinking water to remove carcinogens, particularly, chloroform as the trihalomethanes. At the present time, the process being advocated for removal of these objectionable chlorinated carcinogens is to pass the chlorinated drinking water through large beds of activated charcoal. Such installations are anticipated to have a severe economic impact upon the municipalities where government regulations require this treatment due to the extreme economic burden of installing very large carbon treatment facilities and the additional burden and expense of regenerating and replacing the many tons of activated charcoal required to effectively remove these parts per million and parts per billion carcinogenic chlorinated materials. Thus, it can be seen that this can be expected to cause a substantial increase in the cost of municipal and industrial drinking water. Laboratory and pilot plant tests reported so far show that the chlorinated organic materials expend the activated carbon beds at a very rapid rate. Thus, it is anticipated that extremely high cost will be involved in periodic replacement of the spent beds when regeneration is no longer feasible.
It has recently been proposed to utilize ozone as a pretreatment step for the chlorinated surface water prior to its being fed to the charcoal filter beds. Evidence in one study indicates that the bed lives can be lengthened considerably by such techniques.
Numerous devices and processes have been proposed over the last few years for the treatment of liquid waste streams such as sewage and industrial effluents with direct irradiation, preferably gamma radiation generated from gamma producing sources in order to effect secondary or tertiary treatment of such effluent stream to reduce the biological active content of these streams and also reduce the chemical oxygen demand and the total organic carbon content of these waste streams. However, as far as is known, the proposed apparatus and processes devised so far have not found any appreciable commercial application in the treatment of effluent streams to date.
Work was conducted for a number of years at Brookhaven National Laboratory which was reported in Chemical Engineering Progress Symposium, No. 104, Vol. 66, pages 205-219, published in 1970 in an article entitled "Ozone Synthesis for Water Treatment by High Energy Radiation". This article describes the generation of ozone in a pilot reactor in the Brookhaven U-235 fuel pilot reactor. The economics detailed in this paper indicate a substantially cheaper production cost for ozone generated in this manner than that generated by the conventional electric discharge process. Additionally, the study indicates that sewage and/or drinking water can be treated with ozone generated in this manner after the ozone has been chemically purified to remove the radioactive fission fragments which contaminate the stream as derived from the U-235 loop reactor.
While the above Brookhaven study points a way for a more economical manner of generating ozone and treating sewage and drinking water, the problem remains that radioisotope contaminant fragments must be removed from the ozone stream before it would be practical and feasible to utilize the ozone produced by this process in an economical and safe system for municipal and industrial liquid stream treatments.
Therefore, there is a need for a more simplified and straightforward chemonuclear generator and liquid treatment process which utilizes the ozone produced therefrom, which generator and process will not be subjected to the high cost of the liquification and chemical removal of the isotopic fragments which would not be safe to allow contact with the water to be treated.